Crutch head



May 8, 1934. H.- c. PIRTLE ET AL CRUTCH HEAD Filed Feb. 18, 1933 2 Sheets-Sheet l 1 17 Jaalin .HaPi/"Ue May 8, 1934. H. c. PIRTLE ET AL 57,473

CRUTCH HEAD Filed Feb. 18, 1935 2 Sheets-Sheet 2" ammo/MM Patented May 8, 1934- TAS CRUTCH HEAD Horace C. Pirtle and Louis H. .losiin, St. Petersburg, Fla.

Appiication February 18, 1933, Serial No. 657,430

9 Claims.

This invention relates to the class of crutches and pertains particularly to an improved crutch head.

In the use of crutches the constant movement of the head against the clothing beneath the arm, as the crutch is swung back and forth, results in excessive wear upon the clothing and frequently is the cause of tearing the same. a

The primary object of the present invention is to provide a crutch head which will avoid the foregoing undesirable condition.

Another object of the invention is to provide a crutch head which is so designed that the portion immediately contacting the armpit of the user will remain stationary while the crutch legs are being moved back and forth in use.

A still further object of the invention is to provide a crutch head having two relatively movable parts, one of which is fixed to the crutch legs, While the other is movable relative thereto whereby the said other part may be held in fixed position while the legs are moved.

A still further object of the invention is to provide a crutch head of the above described character, wherein means is provided whereby the relatively movable parts of the head may be conveniently secured together.

With the foregoing and other objects in view the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modi- Figure 2 is a sectional view taken upon the.

'line 22 of Figure 1;

Figure 3 is a view in perspective of the wood unit of the head;

Figure 4 is a View in perspective of the ball track plate which is secured to the wood unit;

Figure 5 is a View in perspective of the ball race plate;

Figure 6 is a vertical sectional View on an enlarged scale through the head rocking element; Figure 7 is a longitudinal sectional view through one cusp of the head showing the method of securing the covering and pad therefor;

Figure 8 is a detail perspective of the upper end of a leg socket.

Referring now more particularly to the drawings wherein like numerals of reference indicate corresponding parts throughout the several views, the numeral 1 indicates as a whole the crutch head embodying the present invention, the upper ends of the legs of the crutch being indicated by the numerals 2,

The head structure comprises a crescent shaped or concavo-convex unit 3 which is preferably formed of wood. The convex face of this unit 3 is cut out from points inwardly of the cusps 4 to 7 form the channel 5 having the substantially transverse end walls 6 and the bottom face of this channel is provided with the two grooves 7 which extend throughout the length thereof.

The upper or concave surface of the arcuate element 3 is rounded inwardly from the sides and has formed centrally therein the longitudinally extending channel 8.

Built up upon the top of the unit 3 and resting in the channel 8 is the pad 9 which is preferably forrned. of sponge rubber and at the ends of the unit the cusps are covered by a less resilent padding material 10- such, for example, as felt, which extends over and down against the under face of the unit and is turned in across the adjacent end walls 6 of the recess 5 as indicated at 11. Secured over the pads 9 and 10 and the sides of the unit 3 is a covering 12 of canvas or other suitable fabric and overlying this is a covering 13 of leather. As shown in Figure 7 the leather is also turned in across the end walls 6 of the channel 5 and as shown in Figure 2 it is turned in from the sides of the unit across the convex face thereof.

Secured in the recess 5 is an arcuate plate which is indicated generally by the numeral 14 and which constitutes the ball track plate of the head structure. This plate is firmly secured against the bottom of the recess 5 and it is pressed so as to form trackways 15 throughout the length thereof and with their concave faces upon the convex side of the plate. These trackways fit into the grooves '7 of the unit 3.

Each longitudinal edge of the ball track plate has integral therewith the rounded inwardly curving flange 16 which extends across the trackway 15 as shown in Figure 2. Intermediate its ends and upon its longitudinal center the plate 14 has an aperture 17 formed which coincides with an aperture 18 in the convex face of the unit 3.

Positioned between the flanges 16 of the track plate 14 is an elongated areuate plate 19 which constitutes the ball race plate of the head structure. This plate is pressed or otherwise formed to provide adjacent each longitudinal edge a ball race groove 20 which is closed at each end as indicated at 21. This ball race plate is of a width slightly less than the width of the ball track plate between the inner faces of the flanges l6 and when it is inserted between these flanges the race ways or grooves 20 have their inner or concave faces opposed to the concave faces of the trackways l5.

Positioned in each of the ball race grooves is a plurality of bearing balls 21 which ride in the trackways 15 as illustrated in Figure 2.

As shown in Figure l the length of the ball race plate 19 is materially less than that of the track plate 14, it being in actual practice preferably a little over half the length of the ball track plate. The ball race plate is thus allowed considerable longitudinal motion along the convex surface of the track plate 14.

Adjacent each end the ball race plate is pro vided with a plurality of apertures 22 in which are secured the pins 23 which are formed integral with the ends of short sleeve members 24 in which the upper ends of the crutch legs 2 are located and secured by the screws 25. While this is the preferred method of securing the sleeves 24 to the plate 19 it is, of course, to be understood that the invention is not to be limited to this method, for it will be obvious that other attaching methods may be employed as, for example, the ends of the sleeves 24 may be welded to the plate 19 if desired.

Midway of its ends and upon its longitudinal center the ball race plate 19 has an aperture 26; formed and secured to this plate is a guide sleeve 27 with one end coinciding with the aperture 26 as shown in Figure 6. The method illustrated for securing the guide sleeve 27 to the plate consists of an annular flange 28 which is integral with the guide sleeve and which is attached by screws or other elements 29 as illustrated.

The inner surface of the guide sleeve 27 is provided with the spaced sockets 30 in each of which is a ball 31 and a spring 32 which normally tends to force the ball toward the center of the guide sleeve. Extending through the guide sleeve is a pin 33 which is provided with a single circumferential groove 34. At its outer end the pin carries the head 35 while its inner end, after being located in the sleeve, is swaged as indicated at 36, to prevent its complete removal from the guide sleeve. This pin 33 is designed to assume two positions in the guide sleeve in each of which it is held against accidental movement by one of the spring pressed balls 31. When it is forced upwardly through the guide sleeve toward the overlying unit 3 and plate 14 carried thereby, when the said unit and plate are in the proper position,

it will pass through the aperture 1'7 and into the recess 18 of the unit 3 and thus hold these units against movement relative to the ball race plate 19. When in this position it will be held by the ball 31 which is nearest the inner end of the guide sleeve and when it is withdrawn or retracted it will be held by the outer spring pressed ball and the unit 3 will be free to move relative to the plate 19.

From the foregoing it will be readily apparent that in the use of a crutch equipped with a head of the character embodying the present invention, when the latching or retaining pin 33 is retracted, the crutch legs may be freely swung back and forth on an arc concentric with the convex face of the unit 3 and this unit with the pad carried thereby will remain in one position against the users armpit. The clothing of the user will, therefore, be free of the constant friction to which it would be subjected if the head were of the usual type which is immovably fixed to the crutch legs and forced to swing therewith while the crutch is in use.

In addition to the present improved crutch head serving to protect the clothing and prevent unnecessary wear thereof it will be readily apparent that the comfort of the user will be greatly increased because of the fact that the armpit will not be irritated by the constant movement of the clothing as would be the case if a fixed head were employed. When the user of the crutch desires to have the head fixed it is merely necessary to force the locking pin 33 upwardly so as to en' 21 as the space between the curved portions of the flanges 16 and the plate 14 with which they are connected is suflicient to give a clearance for the race grooves as shown in Figure 2 and the longi-' tudinal edges of the race plate are spaced from the flanges 16 as is also shown in this view.

Having thus described the invention, what is claimed is:-

1. In a crutch, a head comprising an arcuate body having a recess extending throughout the major portion of the convex side, an arcuate plate 1 secured in said recess, flanges formed throughout the longitudinal edges of said plate and curving inwardly over the convex face thereof, a second areuate plate, means securing the convex side of the second plate with the body of the crutch, said second plate being adapted for free longitudinal movement across the convex face of the first plate and being entirely disposed between said flanges,

and anti-friction elements interposed between the plates.

2. In a crutch, a head comprising an arcuate body having a recess extending throughoutthe major portion of the convex side, an areuate plate secured in said. recess, flanges formed through out the longitudinal edges of said plate and curving inwardly over the convex face thereof, a second arcuate plate, means securing the convex side of the second plate with the body of the crutch, said second plate being adapted for free longitudinal movement across the convex face of the first plate and being entirely disposed between said flanges, anti-friction elements interposed between the plates, and means for coupling said plates together to prevent relative movement therebetween.

3. In a crutch, a head comprising an arcuate body having a recess extending throughout the major portions of the convex side, an arcuate plate secured in said recess and having an aperture therein, flanges formed throughout the lon-' gitudinal edges of said plate and curving inwardly over the convex face thereof, a second areuate plate, means securing the convex side of the second plate with the body of the crutch, said second plate being adapted for free longitudinal movement across the convex face of the first plate and being entirely disposed between said flanges, anti-friction elements interposed between the plates, means for coupling said plates together to prevent relative movement therebetween, comprising a guide sleeve secured to the second mentioned arcuate plate and aligned with an aperture therein, and a pin member adapted to assume two positions in said guide sleeve and when in one position engaged in said aperture in the first mentioned arcuate plate.

4. In a crutch, a head comprising an arcuate plate member secured at its convex side to the body of the crutch, said plate having two longitudinal grooves in the concave face, said grooves being closed at their ends, an arcuate body having a recess in the convex side and between the ends thereof, an arcuate plate secured in said recess, a flange extending throughout each longitudinal edge of the second arcuate plate and curving inwardly over the convex face thereof, said flanges receiving the first convex plate entirely therebetween for movement over the convex surface of the second plate, and bearing balls in each of said grooves in the first plate contacting the convex face of the second plate.

5. In a crutch, a head comprising an arcuate plate member secured at its convex side to the body of the crutch, said plate having an opening therein and further having two longitudinal grooves in the concave face, said grooves being closed at their ends, an arcuate body having a recess in convex side and between the ends thereof, an arcuate plate secured in said recess, said last named plate having an opening therein, a flange extending throughout each longitudinal edge of the second arcuate plate and curving inwardly over the convex face thereof, said flanges receiving the first convex plate therebetween for movement over the convex surface of the second plate, bearing balls in each of said grooves in the first plate contacting the convex face of the second plate, and means for securing said plates against relative movement comprising a sleeve secured at one end to the convex side of the first plate and aligning with the said opening therein, a pin slidable in said sleeve, means for holding said pin in either of two positions, said pin when in one of said twopositions engaging in the said opening in the second mentioned plate.

6. In a crutch, a head formed in two portions one of which is fixed to the crutch body, he other portion having an aperture therein, means to provide a sliding connection between said portions, and a securing pin carried by the fixed portion for engagement in the said aperture in the other portion to secure the portions together.

7. In a crutch having a body comprising a pair of legs, a head comprising an arcuate body having a recess in the convex face which terminates short of the ends of the body, forming end walls, an arcuate plate of the length of and fixed in said recess, a second arcuate plate fixed to said legs and disposed in the recess, the second plate being materially shorter than the first, anti-friction elements between the plates, and means preventing the separation of the plates, said second plate being movable longitudinally in the recess and limited in such movement by said end walls.

8. In a crutch having a body comprising a pair of legs, a head comprising an arcuate body having a recess cut longitudinally in the convex face thereof and terminating short of the ends of the arcuate body to form end walls, an arcuate plate having two bearing ball raceways formed longitudinally of and in the concave face thereof, said plate being of materially less length than the recessand secured to said legs and disposed entirely within said recess, means to provide bearing ball raceways longitudinally of the arcuate surface of the recess, bearing balls disposed in and between the raceways in the recess and those in the arcuate plate, and means secured to the arcuate body and enclosing the edges of said arcuate plate to prevent the latter leaving said recess, the said recess end walls forming abutments for limiting the movement of the arcuate plate in the recess.

9. In a crutch having a body comprising a pair of legs, a head comprising an arcuate body having a recess out longitudinally in the convex face thereof and terminating short of the ends of the arcuate body to form end walls, an arcuate plate having two bearing ball raceways formed longitudinally of and in the concave face thereof, said plate being of materially less length than the recess and secured to said lugs and disposed entirely within said recess, means to provide bearing ball raceways longitudinally of the arcuate surface of the recess, bearing balls disposed in and between the raceways in the recess and those in the arcuate plate, means secured to the arcuate body and enclosing the edges of said arcuate plate to prevent the latter leaving said recess, the said recess end walls forming abutments for limiting the movement of the arcuate plate in the recess, and padding disposed over said end walls against which the ends of the arcuate plate strike.

HORACE C. PIRTLE. LOUIS H. JOSLIN. 

